Floor coverings and the like



A. M. HARRISON FLOOR COVERINGS AND THE LIKE Nov. 21, 1967 2 SheetsSheetl Filed Jan. 25, 1964 INVENTOR Hum Mo/eLE Hflfifilson/ ATTORNEYd 2Sheets-Sheet 2 Filed Jan. 25, 1964 N O S R m O H N E V/ MR 0 M N A AUWMJW AT TO'R NEY United States Patent 3,353,985 FLOOR COVERINGS AND THELIKE Alan Morley Harrison, Welwyn, England, assignor to Welwyn Plastics(1955) Limited, Welwyn, England, a British company Filed Jan. 23, 1964,Ser. No. 339,726 Claims priority, application Great Britain, Jan. 24,1963, 3,100/ 63 2 Claims. (Cl. 11737) This invention relates to floorcoverings, leathercloth, coated paper and the like with especialreference to socalled spread flooring, being sheet material having anupper or wearing surface in the form of an applied thermoplasticcoating.

The base material may be any appropriate kind of fabric, felt, paper,metal foil or indeed any flexible sheet material which can be suppliedin roll form.

The coating is applied in the form of a paste of thermoplastic materialcapable of being cured by heat and is suitably polyvinylchloride, P.V.C.cured by infra-red irradiation after being applied to the moving sheetunder a doctor knife which defines the thickness of the applied coating.

The invention provides for the simultaneous application to the basematerial of coloured paste or coloured pastes of similar character viathe doctor knife, prior to curing, so that a patterned upper or wearingsurface is obtained.

The doctor knife through which the coloured paste is applied may beoscillatable and programme controlled to give variable patterns capableof repetition, and as will be appreciated there may be more than onedifferent colour paste application, but all must be simultaneous withthe application of the matrix of thermoplastic material forming thecoating.

The cured coated sheet material may be given any desired surface finish,e.g. by passage of the coated sheet through suitably engraved rolls.

In the practice of the invention applied to the manu facture of sheetmaterial coated with polyvinylchloride, paste for the matrix isadvantageously supplied by gravity feed from a hopper or by hand to thesurface of the base material as it approaches the doctor knife of thecoating or spreading machine.

The additional pattern forming paste or pastes which may be transparent,white or coloured, may be applied through ducts in or associated withthe doctor blade and may be fed by hydrostatic head from hoppersarranged above the doctor knife, preferably with valves in theconnecting ducts.

The doctor knife is advantageously a composite structure with the ductsfor the application of paste formed by co-operative grooves in matingcomponents of the knife which can be dismantled and separated tofacilitate cleaning.

The ducts are distributed at spaced intervals along the doctor knife,i.e. across the web of material passing through the coating or spreadingmachine, and where provision is made for transverse oscillation of theknife, it is preferred not to interrupt the supply of additional pastebut to remove any surplus at each side of the web by scrapers or similardevices.

It has also been found advantageous to have the holes in the doctorknife of different sizes and this can be done most readily by havinginterchangeable jets fitting into the doctor knife. This furtherincreases the patterns which can be produced and facilitates cleaning.

Programming of the doctor knife oscillation may be effected by areversible electric motor, but the oscillation is preferably effectedhydraulically suitably under the control of a programming device whichmay follow any Patented Nov. 21, 1967 selected one of a plurality ofpatterns moving in synchronism with the passage of the web of basematerial through the spreading machine.

The programme may be in the form of a continuous or non-continuous bandwith perforations or serrated edge.

Alternatively, it may be a rotating disc with perforations, slots orserrations. The band or disc when fed through the sensing head of ahydraulic controller varies the pressure or vacuum set up in the systemand thereby operates the hydraulic mechanism.

Alternatively, the band or disc may interrupt the beam of light in aphoto-electric type of sensing head which in turn operates the hydraulicmechanism.

One embodiment of apparatus for carrying out the invention is shown inthe accompanying drawings in which:

FIGURE 1 is a perspective view of the apparatus.

FIGURE 2 is a side view of a doctor knife taken on the lines IIII ofFIGURE 3 while FIGURE 3 is a front view of the doctor knife and FIGURE 4is a detail view taken in cross section on the lines IVIV of FIGURE 3.

In the drawings 1 represents the continuous web of base material drawnfrom a supply roll 2 over a guide roller 3 and passing under a doctorknife generally designated 4.

The web then passes through an infrared oven 5 to pull-through rollers6, the web being supported during its passage through the oven 5 onfreely rotating rollers 7, 8 and 9.

Above the doctor knife 4 is a hopper divided into two separatecontainers 10a and 10b for polyvinyl pastes of the required colours forthe pattern it is desired to form 11 and 12 are downcomer pipes leadingfrom the containers 10a and 1% respectively to the doctor knife 4.

In this embodiment the main coating of polyvinylchloride paste for theweb is applied to it by hand or from a third hopper by means of a ductor pipe, at a position ahead of the doctor knife where it passes over atable 14 between guards or vanes 20 and 21.

The doctor knife 4 is oscillatable laterally of the web 1 and itslateral position is determined by an hydraulic ram 22 controlled by asensing head 23.

FIGURES 2, 3 and 4 show the doctor knife in greater detail. 24 and 25are front and back plates which are clamped on opposite sides of theblade 38 of the knife by the bolts 37. 26 and 27 are ports through theplates 24 and 25 and provide communication between the downcomers 12 and11 respectively, with galleries 28 formed in the blade 38. Leadingdownwardly from the galleries 28 are ducts 30 terminating in orifices31.

From FIGURE 4 it will be seen that the orifices 31 are formed in steelsleeves 32 which are located in bores 34 formed for the purpose in theblade 38. Before the plates 24 and 25 are fixed to the blade 38 thesleeves 32 are passed from above into the bores 34 by way of the ducts30 and are then rotated until shoulders 33 are engaged in recesses 35.If necessary the lower ends of the sleeves 32 are machined flush withthe lower face of the blade 38. The sleeves 32 are removable forcleaning or replacement and sleeves with orifices of different sizes maybe substituted so that the correct size may be employed for a particularpattern.

36 represents bolts which project into the ducts 30 and may be adjustedto control the flow of material through the ducts from galleries 28 toorifices 31.

The pull-through rollers 6 are driven by a belt or chain 29 from anelectric-motor (not shown) it being understood that their speed ofrotation regulates the rate at which the coated web 1 passes through theinfra-red oven 5.

Iclaim:

1. A method of applying a coating. of thermoplastic material capable ofbeing cured by heat to a base material in sheet form, comprisingapplying a basic coating of thermoplastic material to a moving sheet ofthe base material, passing the moving coated sheet under a transverselyoscillating doctor knife having an operative edge which defines thethickness of the applied coating, simultaneously, and While doctoringthe base coating, applying through transversely spaced separate orificesin said operative edge, additional thermoplastic material of a charactersimilar to the base coating but of a different color; and doctoring withsaid oscillating doctor knife said basic coating and said additionalmaterial while it is being applied to form a patterned coating on saidsheet of base material, and subsequently curing said applied coating.

2. A method according to claim 1 wherein the additional thermoplasticmaterial is applied through at least 4 two longitudinally spaced rows oftransversely spaced separate orifices in the operative edge of saiddoctor knife.

References Cited UNITED STATES PATENTS 2,761,418 9/1956 Russell 118412 X2,932,855 4/1960 Bartlett et al. 1184l2 X 1,726,055 8/1929 Campbell117-37 2,695,005 11/1954 Lewin et al. 118412 2,851,372 9/1958 Kaplan etal 1178 3,006,026 10/1961 Martin et a1 118-8 3,032,008 5/1962 Land etal. 118411 3,155,540 11/1964 Loetfier et al. 11711 X 3,174,183 3/1965Siegel 1188 ALFRED L. LEAVITT, Primary Examiner.

A. GRIMALDI, Assistant Examiner.

1. A METHOD OF APPLYING A COATING OF THERMOPLASTIC MATERIAL CAPABLE OFBEING CURED BY HEAT TO A BASE MATERIAL IN SHEET FORM, COMPRISINGAPPLYING A BASIC COATING OF THERMOPLASTIC MATERIAL TO A MOVING SHEET OFTHE BASE MATERIAL, PASSING THE MOVING COATED SHEET UNDER A TRANSVERSELYOSCILLATING DOCTOR KNIFE HAVING AN OPERATIVE EDGE WHICH DEFINES THETHICKNESS OF THE APPLIED COATING, SIMULTANEOUSLY, AND WHILE DOCTORINGTHE BASE COATING, APPLYING THROUGH TRANSVERSELY SPACED SEPARATE ORIFICESIN SAID OPERATIVE EDGE, ADDITIONAL THERMOPLASTIC MATERIAL OF